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By Dr. Aaron Heckleman, PGY-3UMC Emergency Medicine Residents rotate yearly at Nellis Air Force Base ED, where we frequently see servicemembers recently returned from deployment in the Middle East. While most of their complaints are run-of-the-mill, occasionally we see returning troops with complaints that warrant consideration of infectious diseases they may have been exposed to while in theater, particularly in the Middle East. To that end, here is a review of the “Zebra” infectious diseases reported in deployed and recently returned US servicemembers over the past few years.

Infectious GastroenteritisThis is by far the most common medical ailment that affects troops in theater, with more than half of them getting it at some point. A 2004 study of affected soldiers’ stool found that the majority of cases were caused by the same gastroenteritis-causing pathogens as in the USA (enterotoxic E. coli, norovirus, Shigella, etc). A few, however, had Entamoeba histolytica, Giardia, and Cryptosporidium.1 Other studies of returning troops have also found scattered cases of Giardia.2 Note that unless sensitivity studies say otherwise, none of these pathogens should need antibiotics beyond ciprofloxacin+Flagyl for 5-10 days. If you are going to treat empirically, probably starting with ciprofloxacin and adding Flagyl if there is no response, consider sending a stool O+P and stool culture first. In a patient who has already been treated and continues to have chronic diarrhea, consider post-infectious irritable bowel syndrome, a very common complication of bacterial gastroenteritis.3 A small number of troops have been reported to contract hepatitis E16, and anecdotally from the Nellis attendings hepatitis A has also occurred – as a result some attendings order liver panels on these returning troops with persistent GI symptoms. There have been no reports of any tapeworms, roundworms or flatworms in any returning troops. It is known, however, that the roundworm Strongyloides is endemic in Iraq, and there have been reported cases of acute eosinophilic pneumonia which is sometimes associated with Strongyloides exposure, so consider sending a stool O&P or Strongyloides serology study on patients with unexplained eosinophilia – yours could be the first case report.4

MalariaMalaria, caused by Plasmodium parasites invading the red blood cells, has been reported in several soldiers returning from Afghanistan, though none from Iraq.2 The diagnosis tends to not get made until weeks-months after infection, meaning this is one you could potentially see in a stateside ED like Nellis.5 Anecdotally from several Nellis attendings, it is in fact THE oddball infectious disease you are most likely to see at Nellis (with TB a close second). Soldiers are supposed to take malaria prophylaxis while in theater, but not all do. The malaria coming from Afghanistan is primarily P. vivax (not as fulminant or prone to causing cerebral malaria as the more dangerous P. falciparum), but various resistance patterns have been reported so treatment would best be started in consultation with the ID department that will be following the patient long-term. Symptoms of malaria include fever, malaise, general myalgias, nausea and vomiting; labs should show anemia and/or thrombocytopenia. Do not let the lack of a classic relapsing-remitting pattern (like we all learned in med school) make you miss this diagnosis: that finding is not sensitive for malaria.6 If you suspect possible malaria, thick and thin blood smears are the gold standard lab tests.18

TuberculosisDuring the first Gulf War, 2.5% of US soldiers converted from a negative to a positive PPD test.1 No data are publically available on currently returning soldiers, but it is likely the number is similar. Have TB on your differential for patients with chronic infectious symptoms, especially respiratory.

Cutaneous Leishmaniasis (Baghdad Boil)A surprisingly common infection among troops in Iraq and sometimes also in Afghanistan2,7,8 , cutaneous leishmaniasis is almost always caused by the intracellular protozoan parasite Leishmania major, which is transmitted by the bite of an infected sandfly. Suspect this in a patient with a chronic, painless, non-healing, ulcerative skin lesion or lesions. Don’t let this disease’s exotic nature scare you – it is usually self-limited, rarely spreads to other body systems, and often responds to cryotherapy just like a wart.8 These patients should be referred to dermatology on a nonurgent basis for further testing and treatment; in the meantime they can be given a trial of a topical –azole which may have some efficacy.7 There are no tests you need to send from the ED – dermatology will do a biopsy. The type of Leishmania found in Iraq does not cause mucocutaneous leishmaniasis, which is a feature of South American strains.8 Because of rare cases of Leishmaniamajor being incompletely treated and having a more chronic course, and out of an abundance of caution regarding the more dangerous Leishmania species detailed below, the military bars anybody who has ever been diagnosed with any type of leishmaniasis from donating blood.2

Visceral Leishmaniasis (Kala Azar)This is a much more rare, but much more serious disease usually caused by two other Leishmania species: L. infantum-donovani and L. tropica. They are also intracellular protozoan parasites, are also transmitted by the bite of an infected sandfly, and are also endemic throughout the Middle East. A handful of cases have been reported in returned US troops. 9-11 The course of visceral leishmaniasis is prolonged; the incubation period can range from several months to more than a year after return from deployment.When symptoms do occur, they include chronic fever, night sweats, cachexia, pancytopenia and progressive hepatosplenomegaly.10 These patients are sick, and will likely require admission for IV amphotericin B or other antiparastics. If you suspect the disease, there is a Leishmania serology test, or the inpatient team can arrange for various organ biopsies that the pathologists can examine under the microscope to look for the parasite.

Q FeverCaused by the bacterium Coxiella burnetii, which is endemic in livestock throughout the Middle East. Transmission occurs not from eating contaminated meat, but from inhaling aerosolized bacteria from the animals’ manure, straw, bedding etc. Transmission has also been reported from tick bites and ingestion of raw milk, both of which still involve proximity to livestock. After a 2-3 week intubation period, infection usually causes a self-limited flu-like illness with pancytopenia and a viral-pneumonia appearance on chest x-ray. It can have a fulminant course with severe pneumonia and hepatitis, and the most feared complication is endocarditis.2,13 Several cases of Q fever have been reported in troops in Iraq and Afghanistan.12-14 Consider this diagnosis in a recently returned soldier with a flulike febrile illness who has been around livestock, especially if there is pancytopenia. The test for Q fever is a Coxiella serology, and the treatment is doxycycline. Q fever is not generally transmissible between humans, except for a few case reports of possible sexual transmission.15

BrucellosisThere have only been a few reported cases ofbrucellosis in US troops, but it is endemic to the entire Middle East.2 Brucella bacteria can be ingested, inhaled or percutaneously inoculated, and the disease occurs in patients in contact with infected livestock, especially sheep. After an incubation period of up to a few months, symptoms include relapsing-remitting fever, night sweats (with a strong, peculiar, moldy or wet-hay odor) and migratory arthralgia’s/myalgias.4 After the acute flulike phase, the disease enters an indolent chronic phase in which most any organ system in the body can become involved and all signs/symptoms are very nonspecific. There are no characteristic laboratory findings except for positive Brucella serology, and other than the odd-smelling sweat and proximity to livestock, nothing else unique on history and physical. Treatment is with doxycycline plus streptomycin or doxycycline plus rifampin. Except for rarely reported sexual transmission, brucellosis is not transmissible person to person.16

Something else to be aware of:During Operation Iraqi Freedom/Operation Enduring Freedom, many patients returning from theater with burns and traumatic war wounds ended up with multi-drug resistant bacterial soft tissue infections, especially from the previously little-known Acinetobacter baumanii.17 Much was made of this in the US media at the time, where it was labeled an “Iraqi superbug.” Know that this was mostly a problem restricted to the surgical wards and ICU’s of the military’s major medical centers.2 Recently deployed troops who present ambulatory to the ED with soft tissue infections are unlikely to have this bacterium, and you needn’t alter your initial antibiotic choice out of concern for it.

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